Chlorobenzoquinones (CBQs) are a class of emerging water disinfection byproducts that pose significant risks to public health. In this study, we found that three CBQs (tetrachloro-1,4-benzoquinone, 2,5-dichloro-1,4-benzoquinone, and 2-chloro-1,4-benzoquinone) can significantly aggravate cell death caused by Ras-selective lethal small molecule 3 (RSL3). Further study showed that the cell death caused by CBQs, either alone or in combination with RSL3, was related to iron accumulation and GPX4 inactivation, suggesting the occurrence of ferroptosis. Furthermore, reactive oxygen species are found to play a potential key role in mediating the toxicity of CBQs in CBQs and RSL3-induced ferroptosis. These findings will be helpful in understanding the toxic mechanism of CBQs to mammalian cells.
Ferroptosis, an iron-based cell-death pathway, has recently attracted great attention owing to its effectiveness in killing cancer cells. Previous investigations focused on the development of iron-based nanomaterials to induce ferroptosis in cancer cells by the up-regulation of reactive oxygen species (ROS) generated by the well-known Fenton reaction. Herein, we report a ferroptosis-inducing agent based on arginine-rich manganese silicate nanobubbles (AMSNs) that possess highly efficient glutathione (GSH) depletion ability and thereby induce ferroptosis by the inactivation of glutathione-dependent peroxidases 4 (GPX4). The AMSNs were synthesized via a one-pot reaction with arginine (Arg) as the surface ligand for tumor homing. Subsequently, a significant tumor suppression effect can be achieved by GSH depletion-induced ferroptosis. Moreover, the degradation of AMSNs during the GSH depletion contributed to T1-weighted magnetic resonance imaging (MRI) enhancement as well as on-demand chemotherapeutic drug release for synergistic cancer therapy. We anticipate that the GSH-depletion-induced ferroptosis strategy by using manganese-based nanomaterials would provide insights in designing nanomedicines for tumor-targeted theranostics.
TTIMN NPs prepared based on TTIMN has the function of targeting lipid droplet to induce tumor regression by depleting GSH and inactivating GPX4. Meanwhile, the mode of TTIMN NPs catalyzed the conversion of O 2 −• was also clarified according to in vivo experiments, which indicated it could initiate a series of O 2 −• -mediated bio-catalytic reactions to gain autonomously generated O 2 inside solid tumors. TTIMN NPs sensitized O 2 −• formation even under severe O 2 shortage environment, and a part of it would be converted into highly toxic OH•, subsequently triggering the release of cytochrome c and activating the cascade of the Caspase family that ultimately led to cell apoptosis. Self-generated O 2 inhibited tumor proliferation and metastasis mainly by interfering with HIF-related signaling and downregulating DNA methylation. TTIMN NPs has less systemic toxicity in blood systems and no effect on major organs, and blocked tumor progression by maintaining self-metabolism and immune system stability.
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